Microwave-assisted hydrolysis of lutein and zeaxanthin esters in marigold (Tagetes erecta L.)

Abstract

Saponification of lutein and zeaxanthin was performed by microwave-assisted hydrolysis (MAH) and analysed by ultra performance liquid chromatography. The optimal condition of MAH was studied, and the degradation or isomerization of lutein and zeaxanthin were estimated under MAH. The concentrations of lutein and zeaxanthin in 20 marigold samples were assessed by saponification using traditional heater and MAH, the regression coefficient of lutein obtained by two methods was 0.9688 and that of zeaxanthin was 0.9527. The limit of detection for lutein and zeaxanthin was 0.05 and 0.1 μg/ml, respectively, and the limit of quantification for lutein and zeaxanthin was 0.05 mg/100 g and 0.1 mg/100 g, respectively.

Keywords::

• lutein
• zeaxanthin
• microwave-assisted hydrolysis
• UPLC

Declarations of interest: We are grateful for support and funding from Nature Science of Yunnan Province (2008CD181, 2009AB002) and Agriculture standard plan of China, number 61, 2008. The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.